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Physio 2 > MIDTERM 2 > Flashcards

MIDTERM 2 Flashcards

1
Q

What is the MAIN function of blood

A
  • regenerates connective tissue
  • moves gases, nutrients, wastes, and hormones
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2
Q

Explain blood transportation

A

Blood transports formed elements, dissolved molecules, and ions
- Carries O2 from lungs and CO2 toward lungs
- Transports nutrients, hormones, heat, and waste products

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3
Q

Explain what protects against pathogens and blood loss

A
  • leukocytes, plasma proteins, and other molecules in the immune system protect against pathogens
  • platelets and plasma proteins protect against blood loss
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4
Q

Explain body temperature regulation

A
  • blood absorbs heat from body cells
  • heat is released at skin
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5
Q

Explain body pH regulation

A
  • blood absorbs acid & base from body cells
  • blood has chemical buffers
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6
Q

Explain fluid balance

A
  • water from GI tract is added to blood
  • water is lost through pee, skin, and breathing,
  • fluid is exchanged b/w blood and interstitial fluid
  • proteins and ions help w osmotic balance
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7
Q

3 main components of blood and their percentages

A

Plasma - 55%
Buffy coat - <1%
Erythrocytes - 44%

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8
Q

What does blood plasma consist of

A

Water, proteins, other solutes

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9
Q

What does the buffy coat of blood consist of

A

Platelets and leukocytes

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10
Q

What are the two things that erythrocytes lack and why

A

Lack nucleus and cellular organelles because they are packed with hemoglobin

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11
Q

What is hemoglobin and what does it do

A
  • red pigmented protein
  • transports O2 and CO2
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12
Q

What are the four globins of each hemoglobin molecule

A
  • two alpha chains
  • two beta chains
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13
Q

What is the heme group that alpha and beta chains have…explain how it works

A

Porphyrin ring w an iron ion in the middle
- O2 binds to iron ion in order for each hemoglobin to bind four O2 molecules

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14
Q

Explain oxygen binding to iron

A
  • binding is weak
  • fast attachment in lungs
  • fast detachment in body tissues
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15
Q

Explain CO2 binding to globin protein

A
  • binding is weak
  • attachment in body tissue and detachment in lungs
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16
Q

Explain the 6 main steps of erythrocyte reproduction

A
  1. Stimulus:
    - decrease in blood O2 level
  2. Receptor:
  • kidney detects decreased blood O2
  1. Control centre:
    - kidney cells release erythropoietin into blood
  2. Effector:
    - erythropoietin stimulates red bone marrow which increases the rate of the production of erythrocytes
  3. Net effect:
    - increased numbers of erythrocytes enter circulation while lungs oxygenate them making blood O2 levels increase
  4. ———-:
    - kidney detects increased O2 levels which allows erythropoietin to be released by negative feedback
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17
Q

Due to erythrocytes lacking organelles, what can they not synthesize

A

-proteins for repairs

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18
Q

What is the max lifespan for erythrocytes

A

120 days

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19
Q

What happens to old erythrocytes aka how do they die

A

They get phagocytize in spleen or liver

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20
Q

Why are globins and membrane proteins broken down into aa’s

A

So that body can use them for protein synthesis

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21
Q

How is iron from hemoglobin transported

A

By transferrin protein to liver

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22
Q

What two storage proteins does iron from hemoglobin bind to

A

Ferritin and hemosiderin
*most is bound to go ferritin and is stored in liver and spleen

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23
Q

Where is iron transported when needed for the production of erythrocytes

A

Red bone marrow

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24
Q

6 main anatomical structures controlling heart activity

A

-SA node
-AV node
-Right atrium
-AV bundle
-Purkinje fibers
- R&L bundles

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25
Q

Explain how parasympathetic innervation decreases HR

A
  • starts at medulla’s cardioinhibitory center
  • relayed by vagus nerves
  • right vagus innervates SA
  • left vagus innervates AV
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26
Q

Explain how sympathetic innervation increases HR and force of contraction

A
  • starts at medulla’s cardioacceleratory center
  • relayed by neurons from T1-T5 segments of spinal cord
  • extend to SA, AV, myocardium and coronary arteries
  • increases coronary vessel dilation
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27
Q

2 steps of the conduction system

A

Initiation:
- SA node initiates AP

Spread of AP:
- An AP is propagated throughout atria and conduction system

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28
Q

Cardiac muscle cells- 2 steps

A
  1. The AP
    - AP is propagated across sarcolemma of cardiac muscle cells
  2. Muscle contraction
    - Thin filaments slide past thick ones and sarcomeres shorten within cardiac muscle cells
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29
Q

How do nodal cells in SA node initiate heartbeat

A

They depolarize and generate AP

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30
Q

RMP is about ___mV

A

60mV

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31
Q

What type of cells do not have a stable RMP

A

Nodal cells

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32
Q

Common membrane proteins of nodal cells

A

Sodium/ potassium pumps, calcium pumps, leak channels

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33
Q

Nodal cells- specific voltage gated channels

A

-Slow voltage gated sodium channels
-Fast voltage gated calcium channels
-Voltage gate potassium channels

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34
Q

What are the three steps to SA node cells exhibiting autorythmicity

A
  1. Reaching threshold
  2. Depolarization of AP
  3. Repolarization
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35
Q

Explain autorhythmicity step 1

A

Reaching threshold:
- slow voltage gated Na channels open and Na comes in
- membrane potential changes from -60mV to -40mV

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36
Q

Explain autorhythmicity step 2

A

Depolarization of AP:
- fast voltage gated Ca channels open and Ca flows in
- membrane potential changes from -40mV to just above 0mV

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37
Q

Explain authorhythmicity step 3

A

Repolarization:
- Ca channels close and voltage gated K channels open, allowing K to go out
- membrane potential goes back to rest -60mV
- voltage gated Na channels open at -60mV and process begins again

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38
Q

At rest, how many seconds after the last does one SA node AP start

A

0.8 sec = 75 bpm

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39
Q

Similarities of nodal cells and neurons

A

Both fire AP’s

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40
Q

Differences between nodal cells and neurons

A
  • neurons need stim to fire, nodal cells don’t
  • nodal cells don’t have a stable RMP as they exhibit a pacemaker potential when Na channels open
  • in neurons, AP depolarization is from Na entry while in nodal cells, it’s from Ca entry
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41
Q

AP of the heart- Step 1

A

SA node and atrial myocardium:
- AP generated at SA node.
- AP spreads through gap junctions between cardiac muscle cells throughout atria and to AV node

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42
Q

AP of the heart - Step 2

A

AV node:
- AP is delayed at AV node before it passes to AV bundle in interventricular septum

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43
Q

AP of heart - Step 3

A

Bundle branches and purkinje fibers:
- AV bundle conducts AP to left and right bundle branches and then to purkinje fibers

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44
Q

AP of the heart - Step 4

A

Ventricular myocardium:
- AP is spread through gap junctions between cardiac muscle cells in ventricles

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45
Q

Electrical events of cardiac muscle AP -step 1

A

Depolarization:
- impulse from conduction system opens fast voltage gated Na channels
- Na enters cell changing membrane potential from -90mV to +30mV
- voltage gated Na channels inactivate

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46
Q

Electrical events of cardiac muscle AP - step 2

A

Plateau:
- depolarization opens voltage gates K and slow voltage gates Ca channels
- K leaves cardiac muscle cells as Ca enters
**stimulates SR to release more Ca
- membrane depolarized

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47
Q

Electrical events of cardiac muscle AP - step 3

A

Repolarization:
- voltage gated Ca channels close while K channels are open
- membrane potential goes back to -90mV

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48
Q

Mechanical events of cardiac muscle cells

A
  • Ca enters sarcoplasm from interstitial fluid and SR leading to contraction
    As in skeletal muscle, it binds to troponin and initiates crossbridge cycling
  • Ca levels decrease leading to relaxation
    Channels close and pumps move it into SR and out of cell
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49
Q

T or F: cardiac muscle can exhibit tetany

A

FALSE

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50
Q

Explain refractory period of cardiac cells

A
  • refractory period is long
  • cells can’t fire a new impulse during refractory period
  • plateau phase leads to refractory period of about. 250ms
  • heart cell contracts and relaxes before it can be stimulated again
  • making tetanus contraction impossible
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51
Q

Cardiac cycle- ECG

A

Electrical signals always occur before heart contraction

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52
Q

Cardiac cycle- Left ventricular volume

A

Atrial contraction adds a little more blood to ventricle to increase pumping efficiency

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53
Q

End diastolic volume

A

Greatest amount of blood in ventricle

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54
Q

End systolic volume

A

The lowest amount of blood in ventricle

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55
Q

Cardiac cycle- left atrial volume

A

Atrial pressure is low and relatively steady

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56
Q

Cardiac cycle- Left ventricular pressure

A

Dramatic increase in left ventricular pressure during ventricular systole

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57
Q

Cardiac cycle- left ventricular pressure and volume

A

Left ventricular pressure determines left ventricular vol

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58
Q

Cardiac cycle- Aortic pressure

A

Left ventricular pressure determines aortic pressure

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59
Q

Cardiac cycle- heart sounds

A
  1. Aortic AL valve opens
  2. Aortic SL valve closes (sound. 2)
  3. AV valve closes (sound. 1)
  4. AV valve opens
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60
Q

T or F: capillaries aren’t filled simultaneously

A

TRUE

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61
Q

How is blood flow measured

A

mL/minute

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62
Q

What 4 things are local blood flow dependent on

A
  1. Degree of tissue vascularity
  2. Myogenic response
  3. Local regulatory factors altering blood flow
  4. Total blood flow
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63
Q

What is profusion

A

Amount of blood flow to tissue

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64
Q

Degree of vascularization

A

Extent of vessels in a tissue

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65
Q

What type of tissues have high vascularity

A

Metabolically active tissues

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66
Q

Angiogenesis

A

Formation of new vessels (weeks to months)

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67
Q

Examples of angiogenesis

A
  1. In skel mm in response to aerobic training
  2. In adipose tissue w weight gain
  3. In coronary vessels in response to blockage
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68
Q

Regression

A

Return to previous state of blood vessels

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69
Q

Myogenic response

A

Smooth mm in blood vessel wall keeps local flow constant by adjusting resistance

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70
Q

What kind of chemicals alter blood flow

A

Vasoactive chemicals

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71
Q

Vasodilators

A

Dilate arterioles and relax precapillary sphincters
- increases flow into capillary beds

72
Q

Vasoconstrictors

A

Constrict arterioles and cause contraction of precapillary phincters
- decreases flow into capillary beds

73
Q

Auto regulation & changing metabolic activity

A

When tissue controls blood flow …
When tissue activity increases, stimuli signal inadequate perfusion and act as vasodilators

74
Q

What increases and decreases in auto regulation

A

O2 and nutrient levels decrease
CO2, lactic acid, H, and K increase

75
Q

Auto regulation- negative feedback

A

When perfusion increases, vessels constrict

76
Q

Reactive hyperemia

A

Increase in blood flow after its disrupted
Ex: going into warm room after being in cold

77
Q

BP

A

Force of blood against vessel wall

78
Q

BP gradient

A

Change in pressure from one end of vessel to other
-Highest in arteries and lowest in veins

79
Q

Arterial BP

A

Blood flow in arteries pulses w cardiac cycle

80
Q

What is systolic pressure

A

When ventricle contracts (systole)
- high pressure in arteries
- upper number of BP ratio- 120/80

81
Q

What is diastolic pressure

A

When ventricles relax
- lowest pressure in arteries
- lower number of BP ratio

82
Q

Pulse pressure

A

Pressure in arteries added by heart contraction

83
Q

Mean arterial pressure (MAP)

A

Average arterial BP across cardiac cycle
- =diastolic pressure + 1/3 pulse pressure

84
Q

Capillary BP

A

Pressure no longer fluctuates between systolic and diastolic
- needs to be high enough for exchange of substances
- needs to be low enough not to damage vessels

85
Q

Arterial end of capillary BP number

A

40mm Hg

86
Q

Venous end of capillary BP number

A

Below 20mm Hg

87
Q

Venous return depends on what

A

Pressure gradient, skel mm pump, respiratory pump

88
Q

What is the BP in venues compared to vena cava

A

20mmHg in venues and almost 0 in vena cava

89
Q

Explain how skeletal muscle pump assists venous return from limbs

A
  1. Mm contract, veins are squeezed
  2. Blood is pushed and valves prevent backflow
  3. Blood is moved faster during exercise
  4. Blood pools in leg veins with prolonged inactivity
90
Q

Respiratory pump assists in what

A

Venous return in thorax

91
Q

Explain respiratory pump inspiration

A
  1. Diaphragm contracts, so abdominal pressure increases and thoracic pressure decreases
  2. Blood in abdominal veins is driven toward thoracic cavity
92
Q

Explain respiratory pump expiration

A

1.Diaphragm relaxes, so thoracic pressure increases while abdominal pressure decreases
2. Blood in thoracic cavity veins driven toward heart
3. Blood in lower limbs allowed into abdominal veins

93
Q

Explain poiseuilles law

A
  • Resistance increases as length increases
  • Resistance increases as viscosity increases
  • Resistance decreases as radius increases
94
Q

Function of angiotensin II

A

-Raises BP
- stimulates thirst
- decreases urine formation
- stimulates release of aldosterone and anti diuretic hormone

95
Q

Aldosterone function & where is it released from

A

Increases absorption of Na ions and water in kidney
- released from adrenal cortex

96
Q

Antidiuretic hormone function & released from

A

Maintains or elevates BP
- released from post pituitary

97
Q

Effects of ADH

A
  1. Increases water reabsorption in kidney
  2. Stimulates thirst centre to increase fluid intake
  3. In large amounts it causes vasoconstriction
98
Q

3 blood vessels and their functions

A
  1. Arteries
    Take blood from heart to capillaries
  2. Capillaries
    Exchange substances b/w blood and tissues
  3. Veins
    Take blood from capillaries to heart
99
Q

Tunica intima

A

Inner layer
- ENDOTHELIUM of simple squamous epithelium regulates blood vessel size
- subendothelial layer of areolar connective tissue

100
Q

Tunica media

A

Middle layer
- contraction causes vasoconstriction ( narrows lumen)
- relaxation causes vasodilation (widens lumen)

101
Q

Tunica externa

A

Outermost layer
- helps anchor vessel to other structures
- contains vasa vasorum

102
Q

Explain the structure of arteries

A
  1. Thicker tunica media and narrower lumen than veins
  2. More elastic and collagen fibers
  3. More resilient and resistant to changes in BP
103
Q

Explain the structure of veins

A
  • thicker tunica externa and larger lumen than arteries
  • less elastic and collagen fibers
  • wall collapses if there’s no blood in the vessel
104
Q

Explain the structure of capillaries

A
  1. Contains only tunica intima
  2. Composed of endothelium and basement membrane
  3. Thin wall allows for rapid gas and nutrient exchange
105
Q

Blood vessels (5) biggest to smallest

A
  1. Veins
  2. Arteries
  3. Venues
  4. Arterioles
  5. Capillaries
106
Q

3 basic types of arteries

A
  1. Elastic arteries
  2. Muscular arteries
  3. Arterioles
107
Q

Elastic arteries

A

Biggest arteries
- take blood from heart to muscular arteries
Ex: aorta, pulmonary trunk, carotid, iliac

108
Q

Muscular arteries

A

Medium arteries
- Distribute blood to diff regions
- muscle allows vasoconstriction and dilation
Ex: brachial artery, coronary

109
Q

Arterioles

A

Smallest arteries
- bigger arterioles have 3 tunics
- small ones have only one layer of smooth mm
- smooth mm is somewhat constricted which is called vast other tone

110
Q

Capillaries connect what to what

A

Arterioles to venules

111
Q

continuous capillaries

A

-Endothelial cells make continuous lining
- intercellular clefts are the gaps b/w endothelial cells of capillary wall
- large particles can’t pass but small molecules can
Found in: mm, skin, lungs, cns

112
Q

Fenestrated capillaries

A

-Endothelial cells make continuous lining but there are fenestrations
- fenestrations allow movement of small plasma proteins
- found in: places with lots of fluid transport
Ex: intestine capillaries absorbing nutrients

113
Q

Sinusoids

A
  • endothelial cells form an incomplete lining with big gaps
  • no basement membrane really
  • openings allow transport of big things
    Found in : bone marrow, spleen, endo glands
114
Q

Metarteriole

A

Vessel branch of an arteriole

115
Q

True capillaries

A

Vessels branching from metarteriole
Make up bulk of capillary bed

116
Q

Precapillary sphincter

A

Smooth mm ring at true capillary origin
- relaxation allows blood flow intO true capillaries
- contraction causes blood to bypass capillary bed

117
Q

Vasomotion

A

Cycle of contracting and relaxing of precapillary sphincters

118
Q

Venules

A

Smallest veins
- companions vessels w arterioles
- smallest ones are post capillary venules
- biggest ones have all three tunics
- merge to form veins

119
Q

Blood reservoir percentages

A

70% in systemic circulation at rest
- 55% veins
-10% arteries
- 5% capillaries
- 18% pulmonary circulation
- 12% in heart

120
Q

Simple pathway of blood vessels and give an ex

A

One major artery delivers blood to an organ or region
- arterioles feed into capillary beds
- capillary bed is drained by venules
- venules merge to one vein
Ex: splenic artery delivers blood to spleen; splenic vein drains organ

121
Q

Arterial anastomosis (arterial joining)

A

2+ arteries converge to supply same region

122
Q

Venous anastomosis

A

2+ veins drain same body region

123
Q

Arteriovenous anastomosis

A

Transports blood from artery directly to vein
- allows areas to be bypassed if body is hypothermic

124
Q

Portal system & path

A

Two capillary beds in sequence
Path: artery, capillary bed, portal vein, capillary bed, vein

125
Q

Cross sectional area

A

Lumen diameter

126
Q

Total cross sectional area

A

Sum of diameters of all vessel of a certain type
Ex: total cross editorial area of capillaries is largest bc there are so many capillaries

127
Q

Blood flow velocity

A

Blood flow is slow in capillaries, allowing for exchange b/w blood and tissue fluid

128
Q

What two things do endothelial cells use

A

pinocytosis and exocytosis

129
Q

Bulk flow

A

Fluids flow down pressure gradient
- movement direction depends on net pressure of opposing forces

130
Q

Filtration

A

When fluid moves out of blood
- large solutes are blocked
- occurs on arterial end of capillary

131
Q

Reabsorption

A

When fluid moves back into blood
-occurs on venous end

132
Q

What do hydrostatic and colloid osmotic pressure regulate

A

Bulk flow

133
Q

What does hydrostatic pressure P cap do

A

Forces fluid out of capillary

134
Q

Colloid osmotic pressure of proteins within capillary does what

A

Pulls fluid into capillary

135
Q

Capillary hydrostatic pressure

A

Forces fluid outward thru capillary membrane

136
Q

Interstitial fluid pressure

A

Opposes filtration when value is positive

137
Q

Plasma colloid osmotic pressure

A

Opposes filtration causing osmosis of water inward through membrane

138
Q

Interstitial fluid colloid osmotic pressure

A

Promotes filtration by causing osmosis of fluid outward through membrane

139
Q

P wave

A

Electrical changes of ATRIAL DEPOLARIZATION in SA node

140
Q

QRS complex

A

VENTRICULAR DEPOLARIZATION
Atria is also repolarizing

141
Q

T wave

A

VENTRICULAR REPOLARIZATION

142
Q

What contracts during the PQ segment, and then the ST segment

A

PQ: atria are contracting
ST: ventricles are contracting

143
Q

Atrial repolarization is visible on an ECG… T or F

A

F

144
Q

6 electrical events of the heart

A
  1. Atrial depolarization
  2. Atrial plateau
  3. Atrial repolarization
  4. Ventricular depolarization
  5. Ventricular plateau
  6. Ventricular repolarization
145
Q

PR interval

A

When AP is transmitted through conduction system

146
Q

QT interval

A

Time of ventricular AP

147
Q

What are heart blocks

A

Impaired conduction

148
Q

First degree AV block

A

PR prolongation
- slow conduction b/w atria and ventricles

149
Q

Second degree AV block

A

Failure of some action potentials to reach ventricles

150
Q

Third degree AV block

A

Complete
- failure of all AP’s to reach ventricles

151
Q

Premature ventricular contractions

A

Result from stress, stimulants, or sleep deprivation
- abnormal AP within AV node or ventricles

152
Q

Atrial fibrillation

A

Chaotic timing of atrial action potentials

153
Q

Ventricular fibrillation

A

Chaotic electrical activity in ventricles
When u need an AED

154
Q

Ventricular balance

A

Equal blood amount pumped by L&R sides of heart

155
Q

Cardiac output

A

Amount of blood pumped by a single ventricle in one minute
L/min
Determined by HR and SV

156
Q

Cardiac reserve

A

Capacity to increase cardiac output above rest level

157
Q

Chronotropic agents

A

Change HR
- alter nodal cell activity

158
Q

Positive chronotropic agents function

A

Increase HR
- NE and EPI are released and bind to nodal cells which increases firing rate
- phosphorylated Ca channels enhance Ca influx so cell fires sooner

159
Q

What are the 4 chronotropic agents

A

TRH
Caffeine
Nicotine
Cocaine

160
Q

TRH

A

Increases number of beta 1 adrenergic receptors on nodal cells

161
Q

Caffeine

A

Inhibits breakdown of cAMP

162
Q

Nicotine

A

Increases release of NE

163
Q

Cocaine

A

Inhibits reuptake of NE

164
Q

What are the 2 negative chronotropic agents

A

Parasympathetic activity
Beta blocker drugs

165
Q

What do neg chronotropic agents do

A

Decrease HR

166
Q

Neg chronotropic agents: parasympathetic activity

A
  1. Parasympathetic axons release ACh onto model cells
  2. ACh binds muscarinic receptors which are K channels
  3. Channels open K exits cell making it more neg
  4. Longer time for nodal cell to reach threshold, so HR slower.
167
Q

Neg chronotropic agents: beta blocker drugs

A
  • interfere w EPI and binding to beta receptors
  • used to treat highBP
168
Q

Autonomic reflexes

A

-baroreceptors and chemoreceptors send signals to cardiac center
- cardiac center influences sympathetic and parasympathetic systems to alter cardiac output as needed

169
Q

Atrial reflex

A

Protects heart from over filling
- baroreceptors stimulated by increased venous return
- increased nerve signals to cardioacceleratory center
- increased excitation of sympathetic axons to heart
- HR increase to move blood through quick

170
Q

Stroke volume

A

Amount of blood ejected in one beat
Influenced by: venous return, inotropic agents, and afterload

171
Q

Venous return

A

Volume of blood returned to heart
- determines amount of ventricular blood prior to contraction

172
Q

Frank starling law

A

As EDV increases, the greater stretch of heart wall results in more optimal overlap of thick and thin filaments
- heart contracts more forcefully when filled w more blood so SV increases

173
Q

Inotropic agents

A

Change SV
- alter contractility
- due to changes in Ca available in sarcoplasm
- Ca levels relate to number of Crossbridges formed

174
Q

After load

A

Resistance in arteries to ejection of blood by ventricles
- pressure that must be exceeded before bloods ejected
- atherosclerosis increases afterload

175
Q

Recap- inotropic affects ________ while chronotropic affects ______

A

Inotropic: SV
Chronotropic: HR

Physio 2 (3 decks)

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